Effects of sleep deprivation on brain bioenergetics, sleep, and cognitive performance in cocaine-dependent individuals

MRS study on the correlation between frontal GABA+/Glx ratio and abnormal cognitive function in medication-naive patients with narcolepsy

OBJECTIVE

To compare the GABA+/Glx (glutamate-glutamine) ratio in the prefrontal lobe under non-rapid eye movement sleep between patients with narcolepsy type 1 (NT1) and normal controls and explore the correlation between this difference and abnormal cognitive function, using synchronous electroencephalography-functional magnetic resonance spectroscopy (EEG-fMRS).

METHODS

MRS measurements of GABA+ and Glx concentrations as well as synchronous EEG data were obtained from 26 medication-naive patients with NT1 and 29 sex- and age-matched healthy community volunteers. Cognition was appraised with the Beijing version of the Montreal Cognitive Assessment, and daytime sleepiness was measured using the Epworth Sleepiness Scale. All subjects recorded a 2-week sleep log as well as an overnight polysomnography within 1 week before MR scanning to understand their sleep habits and determine sleep stages. After PSG, they also underwent multiple sleep latency trials. Patient/control group differences in the individual measurements of GABA+ and Glx and the GABA+/Glx ratio and their relationship with cognition were assessed.

RESULTS

The GABA+/Glx ratio and GABA + levels of patients with narcolepsy were higher than those of the control group (P＜0.0001 and P = 0.0008, respectively). However, there was no significant difference in Glx levels (P = 0.6360). The GABA+/Glx ratio negatively correlated with abnormal cognitive function (r = -0.6710, P = 0.0002). Moreover, GABA + levels were inversely proportional to rapid eye movement sleep latency (REML) in patients with narcolepsy (r = -0.5019, P = 0.0106).

CONCLUSION

The GABA+/Glx ratio in the prefrontal lobe was higher in NT1 patients during N2 sleep than in normal controls, mainly caused by GABA + levels; this ratio was negatively related to abnormal cognitive function. In addition, GABA + levels were inversely proportional to REML.

Single dose creatine improves cognitive performance and induces changes in cerebral high energy phosphates during sleep deprivation

The inverse effects of creatine supplementation and sleep deprivation on high energy phosphates, neural creatine, and cognitive performances suggest that creatine is a suitable candidate for reducing the negative effects of sleep deprivation. With this, the main obstacle is the limited exogenous uptake by the central nervous system (CNS), making creatine only effective over a long-term diet of weeks. Thus far, only repeated dosing of creatine over weeks has been studied, yielding detectable changes in CNS levels. Based on the hypothesis that a high extracellular creatine availability and increased intracellular energy consumption will temporarily increase the central creatine uptake, subjects were orally administered a high single dose of creatinemonohydrate (0.35 g/kg) while performing cognitive tests during sleep deprivation. Two consecutive 31P-MRS scans, 1H-MRS, and cognitive tests were performed each at evening baseline, 3, 5.5, and 7.5 h after single dose creatine (0.35 g/kg) or placebo during sub-total 21 h sleep deprivation (SD). Our results show that creatine induces changes in PCr/Pi, ATP, tCr/tNAA, prevents a drop in pH level, and improves cognitive performance and processing speed. These outcomes suggest that a high single dose of creatine can partially reverse metabolic alterations and fatigue-related cognitive deterioration.

Arousal-Mediated Sleep Disturbance Persists During Cocaine Abstinence in Male Mice

Acute cocaine disturbs sleep on a dose-dependent basis; however, the consequences of chronic cocaine remain unclear. While the arousal promotion following cocaine has been well-established, effects of cocaine on sleep after termination of chronic cocaine exposure appear variable in human subjects with few studies in non-human subjects. Here, a within-subjects design (outcomes normalized to baseline, undisturbed behavior) and between-subjects design (repeated experimenter-administered cocaine vs. experimenter-administered saline) was used to investigate sleep homeostasis and sleep/waking under repeated cocaine/saline exposure and prolonged forced abstinence conditions in mice. Overall, during the forced abstinence period increases in arousal, as determined by sleep latency and gamma energy, persisted for 2 weeks. However, the sleep response to externally enforced sleep deprivation was unchanged suggesting that sleep disruptions during the forced abstinence period were driven by enhancement of arousal in the absence of changes in sleep homeostatic responses.

The Acute Readiness Monitoring Scale: Assessing Predictive and Concurrent Validation

To complement and enhance readiness-monitoring capability, the Acute Readiness Monitoring Scale (ARMS) was developed: a widely applicable, simple psychometric measure of perceived readiness. While this tool may have widespread utility in sport and military settings, it remains unknown if the ARMS demonstrates predictive and concurrent validity. Here, we investigated whether the ARMS is: (1) responsive to an acute manipulation of readiness using sleep deprivation, (2) relates to biological markers of readiness [cortisol/heart-rate variability (HRV)], and (3) predicts performance on a cognitive task. Thirty young adults (aged 23 ± 4 years; 18 females) participated. All participants engaged in a 24-h sleep deprivation protocol. Participants completed the ARMS, biological measures of readiness (salivary cortisol, HRV), and cognitive performance measures (psychomotor vigilance task) before, immediately after, 24-, and 48-h post-sleep deprivation. All six of the ARMS subscales changed in response to sleep deprivation: scores on each subscale worsened (indicating reductions in perceived readiness) immediately after sleep deprivation, returning to baseline 24/48 h post. Lower perceived readiness was associated with reduced awakening responses in cortisol and predicted worse cognitive performance (slower reaction time). No relationship was observed between the ARMS and HRV, nor between any biological markers of readiness (cortisol/HRV) and cognitive performance. These data suggest that the ARMS may hold practical utility in detecting, or screening for, the wide range of deleterious effects caused by sleep deprivation; may constitute a quick, cheap, and easily interpreted alternative to biological measures of readiness; and may be used to monitor or mitigate potential underperformance on tasks requiring attention and vigilance.

At the intersection of sleep deficiency and opioid use: mechanisms and therapeutic opportunities

Due to the ongoing opioid epidemic, innovative scientific perspectives and approaches are urgently needed to reduce the unprecedented personal and societal burdens of nonmedical and recreational opioid use. One promising opportunity is to focus on the relationship between sleep deficiency and opioid use. In this review, we examine empirical evidence: (1) at the interface of sleep deficiency and opioid use, including hypothesized bidirectional associations between sleep efficiency and opioid abstinence; (2) as to whether normalization of sleep deficiency might directly or indirectly improve opioid abstinence (and vice versa); and (3) regarding mechanisms that could link improvements in sleep to opioid abstinence. Based on available data, we identify candidate sleep-restorative therapeutic approaches that should be examined in rigorous clinical trials.

Personal Doses of Cocaine and Coca Paste are Adulterated in Cartagena de Indias (Colombia)

Knowledge of drug composition consumed on the streets and the identification and quantification of their adulterants is essential for understanding unexpected side effects, tracking routes, and drug profiling. Therefore, this work aimed to determine the purity and to identify and quantify the main adulterants found in personal doses of cocaine (perico) and coca paste (bazuco) in Cartagena de Indias (Colombia). The data collected in this study describe a first attempt to introduce the qualitative and quantitative analyses of adulterants present in street drugs in Cartagena de Indias to improve surveillance. Through gas chromatography coupled to mass spectrometry (GC-MS), the purity and adulterants were quantified in 45 personal doses of cocaine powder and coca paste. 100% of the personal doses in the city were adulterated; caffeine, phenacetin, and levamisole were the main adulterants identified in cocaine. Besides the above, lidocaine was also found in coca paste. The purity of cocaine varied from 8% to almost 70%, with caffeine ranging from 6% to 42%. In the case of coca paste, the maximum content of cocaine found was 60%, while some samples contained as little as 14%. The results are consistent with other research in terms of the widespread use of caffeine as an adulterant, but they also follow the growing trend of the use of levamisole and phenacetin. The wide range of cocaine content in samples sold in the illicit market could cause undesirable effects on cocaine users who do not know the exact intended dose for consumption; so, this study intends to make these results available not only to academic, public health, and national security agencies but also to tourists entering Cartagena de Indias, so that they are aware of what they are consuming and the risks to which they are exposed.

Interaction between cocaine use and sleep behavior: A comprehensive review of cocaine's disrupting influence on sleep behavior and sleep disruptions influence on reward seeking

Dopamine, orexin (hypocretin), and adenosine systems have dual roles in reward and sleep/arousal suggesting possible mechanisms whereby drugs of abuse may influence both reward and sleep/arousal. While considerable variability exists across studies, drugs of abuse such as cocaine induce an acute sleep loss followed by an immediate recovery pattern that is consistent with a normal response to loss of sleep. Under more chronic cocaine exposure conditions, an abnormal recovery pattern is expressed that includes a retention of sleep disturbance under withdrawal and into abstinence conditions. Conversely, experimentally induced sleep disturbance can increase cocaine seeking. Thus, complementary, sleep-related therapeutic approaches may deserve further consideration along with development of non-human models to better characterize sleep disturbance-reward seeking interactions across drug experience.

Exploring the relationship of sleep quality with drug use and substance abuse among university students: a cross-cultural study

Background

There is a growing interest in studying the area of drugs and college students due to the negative effects that drugs have on a student’s social life, academics, psychology, finances, and health. So, this study aims to identify the relationship between drug/substance abuse and quality of sleep among university students in Yemen and Saudi Arabia.

The sample size was 935 (43.21% N = 404 female, 56.79% N = 531 male, 55.40% N = 518 Yemeni, and 44.60% N = 417 Saudi). Students responded to the Drug Abuse Screening Test (DAST-10), the Pittsburgh Sleep Quality Index (PSQI), and the Substance Abuse Questionnaire.

Results

The results showed a high prevalence of drug use: 43.1% of respondents (27.27% N = 219 Yemenis and 15.83% N = 148 Saudis) abuse drugs, 29.41% were in the low level of drug use, 10.48% were in the moderate level of drug use, 2.46% were in the substantial level of drug, and 0.75% were in the severe level of drug use as per the DAST-10. The differences between both countries in terms of drug use were significant (X2 19.394, P < 0.001). The prevalence rate of inhalants was 16.36% and of sedatives was 12.09%, and the differences between countries were significant. The prevalence of poor sleep quality was 24.81%; a total of 7.91% of respondents had very poor sleep quality, while 16.90% had poor sleep quality. The differences between countries were not significant.

The relationship between sleep quality and drug use, smoking, and substance abuse was significant. The quality of sleep decreased consistently with a high level of drug use or substance abuse.

Conclusions

Poor sleep quality is significantly associated with drug use and substance abuse, and it is important to recognize the factors affecting drug and substance abuse among university students. A significant contribution can make for the protection of university students by guaranteeing that psychological interventions for high-risk groups are planned in advance.

Phosphocreatine Levels in the Left Thalamus Decline during Wakefulness and Increase after a Nap

Scientists have hypothesized that the availability of phosphocreatine (PCr) and its ratio to inorganic phosphate (Pi) in cerebral tissue form a substrate of wakefulness. It follows then, according to this hypothesis, that the exhaustion of PCr and the decline in the ratio of PCr to Pi form a substrate of fatigue. We used 31P-magnetic resonance spectroscopy (31P-MRS) to investigate quantitative levels of PCr, the γ-signal of ATP, and Pi in 30 healthy humans (18 female) in the morning, in the afternoon, and while napping (n = 15) versus awake controls (n = 10). Levels of PCr (2.40 mM at 9 A.M.) decreased by 7.0 ± 0.8% (p = 7.1 × 10-6, t = -5.5) in the left thalamus between 9 A.M. and 5 P.M. Inversely, Pi (0.74 mM at 9 A.M.) increased by 17.1 ± 5% (p = 0.005, t = 3.1) and pH levels dropped by 0.14 ± 0.07 (p = 0.002; t = 3.6). Following a 20 min nap after 5 P.M., local PCr, Pi, and pH were restored to morning levels. We did not find respective significant changes in the contralateral thalamus or in other investigated brain regions. Left hemispheric PCr was signficantly lower than right hemispheric PCr only at 5 P.M. in the thalamus and at all conditions in the temporal region. Thus, cerebral daytime-related and sleep-related molecular changes are accessible in vivo Prominent changes were identified in the thalamus. This region is heavily relied on for a series of energy-consuming tasks, such as the relay of sensory information to the cortex. Furthermore, our data confirm that lateralization of brain function is regionally dynamic and includes PCr.SIGNIFICANCE STATEMENT The metabolites phosphocreatine (PCr) and inorganic phosphate (Pi) are assumed to inversely reflect the cellular energy load. This study detected a diurnal decrease of intracellular PCr and a nap-associated reincrease in the left thalamus. Pi behaved inversely. This outcome corroborates the role of the thalamus as a region of high energy consumption in agreement with its function as a gateway that relays and modulates information flow. Conversely to the dynamic lateralization of thalamic PCr, a constantly significant lateralization was observed in other regions. Increasing fatigue over the course of the day may also be a matter of cerebral energy supply. Comparatively fast restoration of that supply may be part of the biological basis for the recreational value of "power napping."

A systematic review and dose-response meta-analysis of sleep duration and the occurrence of cognitive disorders

PURPOSE

Previous researches have shown inconsistent findings on the relationship between sleep duration and cognitive disorders (including cognitive decline, dementia, Alzheimer's disease, and cognitive impairment). Furthermore, the possible dose-response association of sleep duration and cognitive disorders is still not clear.

METHODS

Two databases (PubMed and Embase) were searched for relevant studies from inception to May 4, 2016. We used the generic inverse-variance method to combine the outcomes with a random-effects model for the association between sleep duration (the shortest or longest vs. middle category) and cognitive disorders. Additionally, we used the generalized least-squares trend estimation model to estimate the potential dose-response association.

RESULTS

Finally, nine eligible cohort studies involving 22,187 participants were included in the present systematic review and meta-analysis. Compared with the middle category, both short and long sleep duration were accompanied by a significantly higher incident risk of cognitive disorders, and the relative risks (RRs) and 95% confidence intervals (CIs) were 1.34 (1.15, 1.56) and 1.21 (1.06, 1.39), respectively. Moreover, an approximately "U-shaped" dose-response relationship was observed. Stratified analyses showed that the association between short sleep duration and cognitive disorders was more robust in the subgroup of the measurement of sleep duration based on self-report.

CONCLUSIONS

The lowest incident risk of cognitive disorders was found at the sleep duration of 7-8 h per day. The present study includes a small number of studies, and the study participants mostly consist of Caucasian population. In the future, researches are also warranted to confirm the association in different groups of people.

Modafinil and sleep architecture in an inpatient-outpatient treatment study of cocaine dependence

OBJECTIVE

To determine whether the increase in slow-wave sleep associated with modafinil treatment in chronic cocaine users mediates improved clinical outcomes.

METHOD

57 cocaine dependent participants were randomized to receive modafinil 400mg or placebo daily during a period of inpatient treatment followed by six weeks of outpatient treatment. Participants underwent polysomnographic sleep recording during inpatient treatment prior to and after starting modafinil. Outpatient treatment consisted of weekly cognitive behavioral therapy. Contingency management was used to promote participation in treatment and research demands, including thrice weekly visits during the outpatient phase for urine toxicology screens and other assessments. The primary clinical outcome was the percent of urine toxicology screens that were negative for cocaine.

RESULTS

Modafinil treatment was associated with a higher mean percentage (52% vs. 26%) of cocaine-free urine screens (p=0.02) and an increase in N3 sleep time (p=0.002). The change in N3 sleep time mediated the higher rate of cocaine-free urine screens. Modafinil treatment was also associated with more consecutive days abstinent during outpatient treatment, greater survival of abstinence, higher daily rates of abstinence, and less sleep degradation typically associated with abstinence from chronic cocaine use.

CONCLUSIONS

Morning-dosed modafinil improves slow-wave sleep in abstinent cocaine users in the inpatient setting, and this effect is a statistical mediator of improved clinical outcomes associated with continued modafinil treatment. The high rates of abstinence achieved in this trial suggest that promoting healthy sleep physiology in an inpatient setting may be important in the effective treatment of cocaine dependence.

The Utility of Magnetic Resonance Spectroscopy for Understanding Substance Use Disorders: A Systematic Review of the Literature

The aim of this article is to present a systematic review of magnetic resonance spectroscopy (MRS) studies of substance use disorders. As a noninvasive and nonionizing imaging technique, MRS is being widely used in substance abuse research to evaluate the effects substances of abuse have on brain chemistry. Nearly 40 peer-reviewed research articles that focused on the utility of MRS in alcohol, methamphetamine, 3,4-methylenedioxymethamphetamine, cocaine, opiates, opioids, marijuana, and nicotine use disorders were reviewed. Findings indicate inconsistencies with respect to alterations in brain chemistry within each substance of abuse, and the most consistent finding across substances was decreased N-acetylaspartate and choline levels with chronic alcohol, methamphetamine, and nicotine use. Variation in the brain regions studied, imaging technique, as well as small sample sizes might explain the discrepancies in findings within each substance. Future well-designed MRS studies offer promise in examining novel treatment approaches in substance use disorders.